Process for decoloring sugar crystals



Patented June 23, 1931 UNITED STATES PATENT OFFICE JULIEN BERG-E, OF TIRLEMONT, BELGIUM, ASSIGNOR TO TIRLEMOINTOISE SOCIE'IE- ANONYME, OFTI'IRLEMONT, BELGIUM, A. CORPORATION PROCESS FOR DEGOLORING SUGAR CRYSTALS No Drawing. Application filed February 11, 1927, Serial No. 167,601, and in- Germany September 8 0, 1926.

In massecuite, more particularly in raw sugar, even after exposure to centrifugal action, certain colouring constituents which, apparently, are enclosed in the outer layers of the crystals, still remain adhering to the crystals and, therefore, after washing can only be removed in a centrifuge, the outer crystal layers being dissolved and separated by centrifugal force. This involves, however, a loss in the yield of, crystal.

The invention consists in a process for removing the colouring constituents, so that this loss of crystals is avoidedl The sugar crystals, freed as far as possible from the adhering mother liquor by centrifugal action (for instance by the use of washing liquid in the centrifuge or aparticularly hlgh centrifugal force such as disclosed in my copending application, Serial No. 167,598, filed concurrently herewith which has resulted in Patent No. 1,775,385,) but not quite colourless, are mashed with a saturated or ap roximately saturated pure white sugar so ution.

The coloured constituents of the crystals pass then completely or almost completely according to the duration of the mashing process into the sugar solution without the crystals, as such, being attacked. At the end of the mashin process the sugar solution is as far as possi le completely freed from the crystal in any suitable manner, for example by exhaustion or centrifugal action. The dyes taken up by the sugar solution can in known manner be again removed from the solution by filtering through animal charcoal, decolourizing charcoal or the like, and can a ain be used for mashing the crystals. If the yes are not sufiiciently removed from the c stals by a single mashing this can be repeate I with a fresh sugar solution.

I claim:

1. A process for removing coloring matter from sugar crystals by means of a pure white sugar solution without substantial loss of crystallized sugar and in-which said solution is maintained in a condition in which it is adapted to be regenerated by passing it through a filter of the charcoal type, comprising first completely freeing the sugar crystals from mother liquor, then mashing said sugar crystals with a pure white sugar solution to remove the coloring matter from said sugar crystals, said coloring matter passing. into said solution, then separating said color bearing solution from said crystals and maintaining said separated solution in a condition in which it may be regenerated bypassing it through a filter of the charcoal type.

2. A process for removing coloring matter V from sugar crystals by means of a pure white sugar solution without substantial loss of crystallized sugar and for maintaining said solution in a condition in which itis adapted to be regenerated by passing it through a.

nature.

JULIEN. BERGE. 

